Hitachi RAS-(2-6)HVNP1(E), Руководство по обслуживанию

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12 Maintenance notes
480
SMGB0087 rev.0 - 12/2013
12.6 Pump-down method for replacing the compressor
No. Procedure Remarks
1
Turn off the main switch of the outdoor unit.
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2
Remove the covers the thermistor the crankcase heater the
power wirings and other items according to the chapter 10.
Make sure that the terminal part of the detached power
supply wires is not exposed by the winding insulation tape
and other items.
3
Attach the manifold to the check joint of the high pressure
side and the low-pressure side of the outdoor unit.
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4
Turn on the main switch of the outdoor unit.
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5
Set the exclusion of the compressor by setting the DSW
so that a broken compressor will not work. You can set the
exclusion of the compressor by setting the DSW1-4 in ON
position.
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6
The compressor replacing mode is performed:
• The DSW1-1 on the outdoor unit PCB→ON (The test
run cooling is running).
• This operation is performed for up to a maximum of ten
minutes.
• If the inverter compressor is excluded the operation
starts after three minutes.
7
The operation finishes when one of the following conditions
occurs:
1. Ten minutes have passed and STP is displayed in se-
ven segments.
2. “08” is displayed in seven segments.
3. When Ps< 0.1 MPa is continued for one minute in ten
minutes STP is displayed in seven seconds and the
operation finishes.
• The operation may finished when any of the conditions
1) to 3) occurs.
8
Close the liquid stop valve completely.
To avoid the spillage of all the refrigerant if the check valve
is broken.
9
Check for a leakage of the check valve on the discharge
gas side:
• DSW4-4 (enforced stoppage of the compressor) → ON
so that the compressor will not run although the run-
ning command is sent from the remote control switch.
• Check that variation of Ps on the outdoor unit PCB is 17
seconds. Make sure that the Ps increase is within 0.03
Mpa in two minutes after the Ps increase at the stoppa-
ge (during approximately five minutes). Also make sure
that Pd > Ps.
• When you stop the compressor for replacing:
• You can check the leakage of the check valve by means
of the Ps variation because the SVA opens so that
the discharge gas side of the inverter compressor can
connect to the low-pressure side.
• 0.03 MPa/2 minutes is within the permissible limits for
the check valve on the discharge gas side.
• The leakage of the check valve may cause an incorrect
brazing due to the gas pressure at the brazing of the
discharge piping.
• If the compressor-replacing mode is performed again set
the DSW4-4 to OFF and keep the DSW4-4 at the OFF
side during ten minutes. Then start according to the
procedure No. 6.
10
Collect the refrigerant by means of the refrigerant collection:
• Perform either A or B depending on the process 9.
A. The leak rate at the process 9 is within the specification
→Collect the refrigerant only at the low-pressure side.
B. The leak rate at the process 9 is greater than the speci-
fication → Collect all the refrigerant of the outdoor unit side
by means of the machine.
• The discharge of the refrigerant in the atmosphere is
strictly forbidden. Make sure that the refrigerant is co-
llected by the collector.
• Keep a note of the quantity of the collected refrigerant.
11
After collecting the refrigerant remove the change hose
(collector side) of the low-pressure side so that the low-
pressure side of the refrigerant cycle will be the atmosphere
pressure.
• Make sure that there is no pressure increase of the low-
pressure sides after collecting the refrigerant.
• Make sure that the refrigerant cycle is the atmosphere
pressure. Otherwise problems such as the blowing of
gas and the suction of the cutting material) may occur
when you are removing the compressors.
12
Turn OFF the main switch of the outdoor unit.
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